Bryan, My hardware is little more complicated, I will explain that below... But wants to make sure that I understood "Local Link". Hope you are not referring to IPv4 address. scp over IPv4 is fine. No issues at all. Only when I use the IPv6, it chokes. scp /tmp/x.iso 172.16.109.50:/tmp completes in less than 3 sec. So almost the same speed that you are referring to. When I use the same two systems and use the second network card (IPv6), then it chokes. ex: scp /tmp/x.iso [a:b:c:d::e]:/tmp/ FAILS or completes in 1+ Hr :-( So The issue I am referring is all about the IPv6 network addresses. Coming to my hardware.... It is all on a ESX server. All these VMs ( freebsd, Ubuntu Linux boxes are on a single ESX server with VMware VM's.) Logically speaking they are all on a single Hardware. I tried between Multiple VMs freeBSD to different Ubuntu Servers ( within the same ESX and also VM resides in different ESX. No issues. When I copy from one Ubuntu to other Ubuntu server using IPv6, then only the issues shows up. I will attache/share some more facts / data tomorrow. HTH Prasad On Apr 2, 2009, at 8:45 PM, Bryan McLellan wrote: > Using only linklocal addresses I've sustained near 40MB/s copying a > 10GB > file in the following patterns: > > Ubuntu 8.10 -> Ubuntu 9.04 > Debian 4.0 -> Ubuntu 9.04 > Ubuntu 9.04 -> Ubuntu 8.10 > > It seems more likely that your problem would be a hardware issue. > > Have you tried connecting the two Ubuntu machines directly together to > rule out any network equipment between the two? > > Have you tried to copy from your FreeBSD machine to more than one > Ubuntu > server to rule out a problem with that installation or hardware? > > Any other testing that could possibly narrow it down? Thanks! > > -- > SCP over IPv6 address is very Slow. Takes Hours > https://bugs.launchpad.net/bugs/352841 > You received this bug notification because you are a direct subscriber > of the bug. > > Status in “openssh” source package in Ubuntu: New > > Bug description: > Binary package hint: openssh-server > > Hi, > > I am using Ubutu Hardy release 8.04 and openssh 4.7P1 > > > lsb_release -a > No LSB modules are available. > Distributor ID: Ubuntu > Description: Ubuntu 8.04.1 > Release: 8.04 > Codename: hardy > root@htaf1:~# > OpenSSH_4.7p1 Debian-8ubuntu1.2, OpenSSL 0.9.8g 19 Oct 2007 > > > When I copy a 50+ MB file from one system to another Ubuntu > > Using IPv4 address it took just less than 3 sec. > Same thing over IPv6 took more than an hour ( 1 Hr and 20 Min) > > I copied the file using local IPv6 address. It ran fine. May be it > is using loop back, instead of real IPv6 address > > > When I initiate the same from a free BSD box to BSD It took less > than 3 sec on both Ipv4 and IPv6. > I can also copy from Ubuntu to a FreeBSD box faster both Ipv4 and > IPv6 addreses. > > I just can't copy the same from a Ubutu to Ubutu or other machines > to Ubuntu over IPv6 address. > > It is very critical for our product :-( > > I even tried getting the latest OpenSSH package from openssh.org > and compiled that module and ran that sshd. > Still no use. Same old behaviour. > > It starts negotiating at 1.5 Mb/ sec and slowly drops to few KB / > sec and stalls the copy process during the time. > > Any updates or known issues. > > thanks in advance for your information on this issue. ====== Together we can build a better process ======= Prasad Tadi